Proprioception in total, hemi- and reverse shoulder arthroplasty in 3D motion analyses: a prospective study

The aim of the study was to assess proprioception after shoulder arthroplasty. Twenty-six patients were enrolled who underwent total shoulder arthroplasty (TSA) (n = 13) or hemi-arthroplasty (n = 8) for shoulder osteoarthritis or reversed arthroplasty (n = 5) for cuff tear arthropathy. All patients were examined before the operation and then again six months thereafter in a motion analysis study with an active angle-reproduction (AAR) test. In all groups the AAR deteriorated at 60 degrees flexion (from 5.5 degrees [SD 2.8] to 7.6 degrees [SD 2.7]; p = 0.007) and at 30 degrees external rotation (ER) (from 6.5 degrees [SD 3.6] to 7.3 degrees [SD 4.8 degrees]; p = 0.023) six months after surgery. In the subgroup of TSA, there was deterioration at 30 degrees ER (p = 0.036). Otherwise, there were no significant changes within or among the subgroups. Proprioception, assessed by the AAR test, remained unchanged or deteriorated six months after shoulder arthroplasty. This might be related to the reduced pain or to the relatively short follow-up period.